Field
The present disclosure relates generally to communication devices, and more particularly to an electronics interface for a device headset jack that switches jack pins to different device circuitry depending on the type of accessory connected to the jack.
Background
The use of the headset jack for applications including audio input, audio output and other accessories is addressed. Accessory devices that provide application such as biometric sensing, environmental sensing, and financial transactions may be connected to any a headset jack such as a standard 4-pin 3.5 mm audio jack. Most of these accessory devices use the open interface of headset jack and the audio coder-decoder (codec) on the chip-set to operate. A disadvantage of such operation arises from limitations, such as output current or output bias-voltages, inherent in the audio codec. To compensate for limitations of the audio codec, these external accessories may require additional circuitry and complexity. For example, if multiple sensors are connected at the same time, more output current/power may be needed than the codec circuit may be able to provide. Or there may be accessory devices which may require output voltage totally different from what codec circuits may be able to source. Or these accessories may require digital input/output signaling.